Method of handling material



Patented Jan. l2, lgg

UNITED STATES :DONALD s. MULLN, or PITTSBURGH, PENNSYLVANIA.

METHOD 'OF HANDLING MATERIAL.

Application flledMaTch 5, 1925. Serial No. 13,126.

To all whom t may concern.'

Be it known that I, DONALD S. MULLIN, a citizen of the United States, residing at Pittsburgh, county of Allegheny, and State of Pennsylvania, have invented a new and useful Improvement in lvlethods yof `Handling Material, of whichthe'following is a full, clear, and exact description.

The present invention relates broadly to material handling, and more particularly to an improved method of effecting removal of a layer of surface material, suchl as frequently referred to as overburden, to permit access to a sub layer or stratum of` coal or other desirable material..

At the present time, itis customary in the art to which the present invention relates to run a track substantially parallel to the edge of the overburden to be removed, and preferably a few feet therefrom, to safeguard the track in the event of slides or the like. Thereafter, a large stripping tool, which may be in the form of a steam shovel, is positioned beside the track at a point sufficiently removed laterally therefrom to provide the desired clearance between the track and the side of the tool. This tool is then operated, and the removed waste material or overburden is carried to a point on the opposite side of the track, and usually initially deposited at a distance representing substantially the maximum reach of the shovel, where a shovel is the type of tool being utilized.

It has heretofore been considered poor practice to permit the pile of waste material to be in advance of the shovel. As the Waste material is in the form of a ridge having sloping sides representing approximately the angle of repose of the material, it is obvious that the peak of the ridge is considerably higher than the average top level of the overburden. This requires the shovel arm to be fully extended for each dumping operation, in orderI to raise the same to the peak of the ridge each time. rlhis operation represents an actual elevation of every cubic foot of material being handled to a point above the pointfrom which it was excavated. Due to the relative positions of the shovel arm and the shovel boom, when the shovel arm is fully extended, the cables utilized for hoisting` purposes, exert a tremendous pull inwardly on the shovel arm, while the shovel operating motor is acting in opposition to this pull. The necessary effect Vis=to.-strain. .all

the operating parts of theentire apparatus to substantially thepoint of maximum endurance. This is obviously poor practice, and inevitably results in Avan exceedingly high operating cost and upkeep. y

`Furthermore vsince the' shovel ,isfalways dumped at a point substantially,.oppositeor slightly iny back` of; the .centery of. rotation of the shovel, the shovel necessarily swings through an average angle for each dumping operation` of j greater than- 900. This represents unnecessarygtime forthe swin-gVunnecessary power expenditure, particularlyas the shovel `arm is-fully or substantiallyfully extended, and .unnecessary .wear not only on the circle track but also on theV otheroperating parts of the apparatus.

This 4manner ofv `discharging material, in additionto being both wastefuland.y costly, is extremely l1azardous,due to theifact that ordinarily a number `of* operatives are rpositioned between the excavating tooland the ridge, thereby placing them directly in the path of falling particles, or rollingstones which frequently cause a great deal of damage.

My present invention has for certain of its objects improved eiiciencyin thehandling of such Waste material, decreased time in the handling of each unit of material, increased tonnage in the -material being handled together withA a material saving in the cost not only of operationbut also of upkeep. In accordance with the present invention, the improved method of operation also results in measurably greater safety to the operatives and equipmentl with far less likelihood of any injury to either. AIn actual-practice, I have found that it is` possible to utilize an 8 yard shovel, for example, with apparatus designed for Va 6 yard shovel, due to the fact that my; improved method does not subject any ofthe working parts to the tremendous strains to which they have heretofore been continuously subjected in operation.

Also, according to prior practice, it has seldom, if ever, been possible to effect a complete shovel cycle, representing travel of the shovel from the point at which the digging is initiated to the point lof dump and return to the pointinitially referred to, in less than `seconds, the average time being about 5a seconds. IIn accordance with my improved invention 'l have frequently made complete cycles of operation in as low as 20 seconds, under exactly the same operating conditions with the same material and the same equipment, my average time for each cycle being approximately l0 seconds. This represents a material saving in time, wear and strain on the hoist cables especially, in addition to vthe saving and wear on other parts of the equipment, and also represents an actual `saving in power of approximately 60%.' Obviously, this involves an increase in the number of cubic yards of material handled per tool with a consequent decrease in the entire cost of operation conr. mensurate therewith.

Exactly the same principles and advantages as those heretofore pointed out are obtained with other types of ymaterial handling apparatus such, for example, as locomotive cranes either of the clam shell or orange peel bucket variety, with drag line apparatus or with gantry cranes or the like constructed for handling material of the character-herein contemplated. It will be understood,l therefore, that throughout the specification and claims I utilize the expression tool in its generic sense as deiinitiveY of a structure capable of performing the functions contemplated irrespective of the construction of such tool or its specia commercial designation.

In the accompanying drawings I have shown for pur oses of illustration only, certain preferre embodiments of the pres ent invention, it being understood that the drawings are largely diagrammatic and that they do not represent or define the. limits of my invention as changes in the constructionof the apparatus and operation thereof may be made without departing either from the spirit of the invention or scope of my broader claims.

In the drawings:

Figure l is a diagrammatic top plan view representing one method of handling mate rial in accordance with the present invention by the utilization of a tool of the shovel are.;

Figure 2 is a side elevaton illustrating a portion of the operation shown in Figure l, and.

Figure 3 is a diagrammatic view representing the operation of a tool, for example, of the drag line type.

In carrying out the present invention., there may be utilized the usual track T adapted to run substantially parallel, and in spaced relationship, to one edge of the material M to be removed, and, usually 're-- ferred to as overburden. In other cases, the track may be entirely dispensed with, and positioning of the equipment modified accordingly. Y

Where the .track is provided, the tool 2 s positioned at one side thereof with its material oi' overburden will be removed by the positioning of the tool illustrated in Figure 1. .In accordance with preferred practice, the distance between these circles will bein the neighborhood of 8 feet.

In carrying out the present invention, the tool will initially be operated to remove that portion of the material indicated as first cut in Figure l of the drawings, this being the portion of the material at the out side corner of the overburden and similarly designated in Figure 2. This operation is repeated until the complete upper layer or bench B is entirely removed throughout the width of the strip of overburden which is being operated upon bythe tool. f After each cut or shovelfull, the shovel arm is retracted, f'

and the entire boom thereupon swung `in a counter clockwise direction as viewed in Figure 1 to bring the shovel over a point P on the opposite side of the track T, where such track is provided. It will of course be understood that where the track is not utilized, a corresponding position may be determined upon. line 8 represents the approximate shape of the end of the ridge of waste material, the peak thereof being indicated by the line 9. The line 10 extending substantially parallel to the line 9 represents the peak of a ridge of waste material removed. in a previous stripping operation.

The disposing of material at the point P is continued until such time as the material, building'up in accordance with the natural laws of repose of such material extends to the limit line 1l which it is desired to have this outer edge of the material reach. Thereafter, successive cuts of material Will be discharged at points P2, P", etc. contiuously along the dotted line 12.

From a careful consideration of the diagrammatic illustration in Figure l it will be apparent to those skilled in the art that the deposit initially at the point l) involves a radical departure from prior practice and is responsible for many advantages inherent In Figure l, the curved in the handling of material in accordance with the present invention. In the first place, the ypeak of the pile of material coinciding with the point l) is materially lower than Y the vvcorrespfmding..point from which the material `is excavated by the tool. This means thatthe tool is not required to raise any of this material above the point of its removal in order to eflect discharge thereof. Furthermore, this initial comparatively small pile of material forms a protective barrier intermediate the main peak of 'the material and the tool, effectively preventing large rocks and the like trom subsequently rolling ontothe workmen, it being apparent that points P2, P3, etc. represent progressive points beyond the peak of the ridge established by each preceding dumping operation. rlhis insures the rolling of the discharged material away from the tool. instead of toward the tool in the manner heretofore inherently necessitated.

After the first bench B has been entirely removed, during which process the shovel. arm is always in substantially its retracted position before referred to as distinguished from a for yardly crowded position as represented by present day operations, a series of second cuts as corrcspondinglyv indicated in Figures l and 2 will be removed until a second bench B is carried away and discharged.

During removal of the second bench, the shovel arm is at a substantially intermediate position, at which there is no appreciable strain on the apparatus and at which it may be easily manipulated and swung as required. Thereafter the third bench B2 lwill be removed by a series of third cuts correspondingly indicated in Figures l and 2. To effect the removal of this portion ofi the overburden, the shovel will be at a more extended position, not representing, however, its maximum extension. As the material of benches B and B has been removed, the point of discharge has gradually travelled up the curved line l2 to a point adjacent the peak 9. This peak 9, however, has not been reached and therefore it is obvious that it has not been necessary to raise any of this previously removed material above the normal level of the overburden in order to efliect its discharge at the desired point. As the third bench approaches complete removal, thek peak 9 is approximated so that theoretically for the last shovellull of material only will it be necessary to exert the apparatus to the extent required to deposit the same at a point .corresponding to the elevation oie the peak. Prior to this final shoveltull, the tool has been operating within normal limits ot' operation without substantial strain and with corresponding ease of manipulation accompanied with a minimum power consumption.

'lhe operation before described involves another advantage in that for the initial lvcuts of material the swing of the tool is through a comparatively small angle, this being necessarily the case as the deposit is initiated at a point closer to the point of removal than is the case, in accordance with established practice, where this material carried each time to the peak, discharged thereon, and permitted to roll to its natural position of rest. As an actual matter of practice, the included angle of swing for these initial cuts is in the neighborhood of only l5@ as contrasted with an included angle ot 900 or more necessitated in accordance with prior practice. lt will readily be seen that this means the removal of an equivalent amount ofivinatcrial with a mini.- mum power consumption and wear on the equipment.

After vall ol the benches have been removed, the tool will be moved ahead along its established line of operation to a point substantially ll feet in advance of that previously occupied. the new point ot' discharge p to a point substantially 8 feet in advance of the point l). rlhe operations and cycles before referred to in connection with they preceding operation will vthen be repeated, and this will be carried out until the. entire amount of the overburden has been effectively displaced and deposited.

ln Figure 3 of the drawings I have indicated diagrammatically the contour ot a pile of waste material ldof the type which will be formed by a tool l5 of' the drag line type, it being understood that the only difference in operation is that represented by a convex line of deposit for the shovel type of excavator as contrasted` with a concave line of deposit 16 for a tool of the drag line type.

`Furthermore, the present invention is distinguishable from methods heretofore practiced in that itrepresents `a discharge o't material initially in the most convenient point `as distinguished from the universally established practice of always carrying the material to the highest point of discharge which necessarily is the point furthest removed from the material in its original location. The advantages of the invention therefore are those which are inherent in the conservation of power and the decrease in upkeep represented by an effective handling of material in such manner that the majority of the material does not have to be raised above the plane of its removal and in which the operation is such that previously deposited material tends to safeguard both the equipment and the operatives.

These advantages also represent a corresponding saving in wear and strain on the equipment, a decrease in the upkeep cost otl the equipment as well as the reduction of the power consumption to a minimum.

l claim:

l. The method oit handling material, coinllhis in turn will bring prising moving a stripping 'tool to a predetermined p sition, initially operating said tool to remove an upper bench or' the material, carrying said material by the stripping tool laterally from the point oitl removal, and depositing said removed material from a point not higher than the point from which it was removed, substanitally as described.

The method of handling material, comprising moving a stripping tool to a predetermined position, initially operating said tool to remove an upper bench of the material, depositing said removed material from a point not higher than the point from which it was removed, and thereafter progressively depositing said material at points rearwardly of said initially deposited material with respect to the position of the strippingA tool, substantially as described.

3. rlhe method of stripping material, comprising moving a stripping tool to a predetermined position, initially operating the same to remove an upper bench of the material, depositing said material from a point not higher than the point rom which it was removed, removing successive benches of such material, and discharging successively removed material at a point beyond the initial point of discharge7 substantially as described.

et, The method of stripping material, comprisng moving a stripping tool to a predetei-mined position, initially operating the same to remove successive cuts in an upper bench of the material, carrying said material by the stripping tool laterally from the point of removal, and depositing said material from points not higher than the point from which it was removed, substantially as described.

5. The method of stripping material, comprising moving a stripping tool to a predetermined position, initially operating the same to remove successive cuts in an upper bench of the material, and depositing said material from points not higher than the 1, 569, roo

point from which it was removed, the point-s ot' discharge for the material being `progressively further from the tool than the-point of initial deposit, substantially as described.

G. The method of stripping materia-l', comprising moving a stripping'tool to a predetermined position, initially operating the same to remove an upper bench of material, and depositing said material by the ftripping tool at a point opposite the point ot removal andk in advance of the axis 'of rotation or the stripping tool, substantially as described. Y

'i'. rl`he method oit' stripping material, comprising moving a stripping tool to aV predetermined position, initially operating the saine to remove an upper bench of material, depositing said material at a point opposite the point of removal and in advance or the axis of rotationof the stripping tool, and thereafter removing successively lower benches ot.' material, and moving the points el deposit rearwardly as successive benches are removed, substantially as described.

8. lhe method of stripping material, comprising moving a stripping tool to a predetermined position, initially operating the same to remove an upper bench of material, depositing said material at a point opposite the point of removal and in advance of the axis ot rotation of the stripping tool, and thereafter removing successively lower benches oit material, and moving the points of deposit further from the axis of rotation or a tool, substantially as described.

9. rlhe method of removing material, comprising depositing the removed material at points progressively beyond the point of initial deposit, whereby the material initially deposited serves as a barrier intermediate the tool and the deposited material, substantially as described.

In testimony whereof I have hereunto set my hand.

DONALD S. MULLIN. 

